A Conversation With FDA's Human Factors and Accessible Medical Technology Expert

The US Food and Drug Administration (FDA) released its Draft Guidance for Industry and Food and Drug Administration Staff-Applying Human Factors and Usability Engineering to Medical Devices to Optimize Medical Device Design on 22 June 2011. According to this document medical device manufacturers must perform appropriate human factors engineering and usability testing on their products.

To help device makers and regulatory professionals working with devices better understand the requirements, RAPS will host the virtual program, Understanding Regulatory Requirements for Human Factors Usability Testing, 7 June. The program will feature a panel of experts including Molly Follette Story, PhD, human factors and accessible medical technology specialist with FDA's

Center for Devices and Radiological Health, Office of Device Evaluation. Regulatory Focus had an opportunity to talk with Story recently by phone and email. Following is an edited transcript of that exchange.

Regulatory Focus: What is human factors engineering and usability testing?

Molly Follette Story: Human factors engineering applies to the evaluation and optimization of interactions between humans and machines related to safety, machine effectiveness, task efficiency and user satisfaction. Usability testing is a term used for human factors evaluations in which people interact with the machine in order to identify design shortcomings. Usability testing is most effective when it is conducted repeatedly throughout the design development process to inform design decisions.

RF: What is FDA looking for with regard to human factors engineering and usability testing?

MFS: FDA encourages medical device manufacturers to include human factors engineering in the processes they use during device development, as appropriate for a specific device. However, FDA reviews human factors data in premarket submissions only for devices that have moderate or serious hazards associated with use of the device. As part of the design development process, FDA expects device manufacturers to conduct a comprehensive hazard/risk assessment and determine whether use errors or failures could cause death or serious injury to the device user or the patient. If so, the manufacturer should conduct a human factors validation study to demonstrate that the intended users would be able to use the device safely and effectively under realistic conditions of use and all use-related hazards have been adequately controlled.

RF: What is new or different in FDA's latest guidance on this? What are its key points?

MFS: The draft human factors guidance document we released in 2011 focuses on the human factors engineering process as applied to the design of medical devices. It presents the range of human factors issues manufacturers should consider during device design, mentions a variety of methods useful for early analyses and usability testing, and goes into substantial detail regarding methods we recommend manufacturers use when they conduct human factors validation studies. The document also provides an outline for organizing human factors data in a premarket submission to FDA, when such data are required.

RF: What are the main human factors engineering and testing considerations for companies developing medical devices?

MFS: The primary goal of human factors engineering in medical device design development is to ensure that the device will be safe and effective to use. In order to achieve this, it is important to identify and understand the intended users of the device and the tasks they must perform to use the device effectively. It is also vital to focus on the hazards involved in the use of the device and to eliminate or control the hazards adequately. For human factors validation studies, the participants should be representative of the intended users and should be allowed to interact with the device under realistic use conditions and in a natural manner, without interference or influence by the study administrators. Finally, the results of the validation study should be analyzed qualitatively to assess the clinical implications of any use errors or failures that occurred and determine whether any modifications are needed to the design of the device, its labeling, or the user training. While no device can be made to be completely error-proof and risk-free, human factors engineering can reduce the likelihood and the potential clinical consequences of use error.